big block Mercedes

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shredator
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big block Mercedes

Post by shredator »

Hello,
My car is another 24 hours of LeMons racecar. It is an 84 mercedes 300d, and it has a 77 Chrysler 440ci engine in it. We had our first race in Sonoma on Dec 7th and 8th, where both 'judges' at the race practically demanded that it be turbocharged. Ever aiming to please the high court, I began to see what that would entail. I have 2 Holset he-351ve turbos, which seem to be well suited for my displacement and rpm. I was originally going to keep the engine carbureted, but due to the location of the engine (set back quite a ways, carb is a few inches behind windsheild) the thought of having pressurized air fuel mixture so close to the driver makes me a bit nervous. So I'd like to fuel inject it. I have been wanting to jump into a Megasquirt project for a while, but the proprietary-ness and expense of the boards has always been a turn off. So here I am...

I think that Ill try to start by making the ecu control injectors, in batch-fire, so that the ecu doesnt need to know the orientation of the engine. Eventually I'd like to modify a distributor to serve as a cam position sensor, and then have the ecu control sequential injection, ignition timing, and servos on the vnt turbos. Someday, If i ever learn how to code worth a damn, I think it would be cool to try and include some sort of self-tuning algorithm, using accelerometer input, but who knows if i'll ever get there.
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AndreyB
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Re: big block Mercedes

Post by AndreyB »

So we are talking a http://en.wikipedia.org/wiki/Mercedes-Benz_W123 with a 7.2 liter engine like http://en.wikipedia.org/wiki/Chrysler_B_engine#440 ? OMG.

1977. What kind of sensors do we have on this engine? Looks like you have a crankshaft sensor of some kind? Do you know the type & the pattern?
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shredator
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need some help selecting sensors/parts

Post by shredator »

Yeah 1977. I think the only sensor it has is an electronic distributor, that has a hall-effect sensor in it in place of points. I'm thinking that If I can, I'd like to ditch that, adapt some sensors to the engine somehow, and go with coil-on-plug.

Since I'm going to have to adapt all necessary hardware to this engine myself, I'd like to get recommendations for readily-available sensors that will work with this ecu. So if anyone knows that, for example, "the GM map sensor from a 2003 ls-whatever is cheap and should work with this ecu" Id like to hear about it!

I have my discovery board, and have loaded firmware onto it.
I have built a 12-channel op-amp input board, and four 6-channel injector driver boards.

So far I'm guessing that i need:
A coolant temp sensor
An air temp sensor
A cam position sensor, unless I can grind some of the "points" off of the reluctor in the distributor, and use that...
Do I need a crank position sensor too?
A MAP sensor, I think i'll get a 3 or 4 bar one from summit?
Injectors? Anyone know of cheap ~30lb/hr injectors?
fuel pump? the one I have is designed to supply a carburetor.
Spark coils? and are other parts necessary between the injector driver boards and the coils? What works best here?

Thanks for any direction that anyone can give!
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AndreyB
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Re: big block Mercedes

Post by AndreyB »

Do you have more cash or more time? Meaning what is your attitude towards junk yards?

I'd suggest we forget about CLT and IAT, that's the easiest and less critical stuff.
Crankshaft sensor is not required. The more events you have is better, but my Ford Aspire works with just five events per camshaft.

I think it's a great idea to go with something we know works, and realistically I suggest we focus on shaft position sensors - 'triggers'. How about
Image

Do you think you can somehow mount these disks on a shaft? There are more pictures here

Another option which is known to work perfectly is 1995 Dodge Neon - I have no idea how that stuff looks like, but I know that we have connected these sensors and they have worked right away. I am sure Noel can provide some pics if you ask him.

Here is a cheap or even junk yard COP option.
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shredator
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Re: big block Mercedes

Post by shredator »

I have read of folks adapting a cam position sensor from a 4.0 jeep engine to my engine. The jeep sensor looks like it is similar to the one you mention above, but only has one "disk" and provides 2 events per cam rotation, an 'on' and an 'off', roughly 180 degrees apart.

to provide more events per crank rotation, I was thinking of using the flywheel teeth as a crank trigger. It has 143 teeth. I found an easy place to drill through the bellhousing to point the tach pickup from a mercedes diesel engine at the teeth. Not sure how to test to see if i get an acceptable signal from that. I dont have an ocilloscope. is an AC voltage good enough?
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Re: big block Mercedes

Post by AndreyB »

shredator wrote:It has 143 teeth. I found an easy place to drill through the bellhousing to point the tach pickup from a mercedes diesel engine at the teeth. Not sure how to test to see if i get an acceptable signal from that. I dont have an ocilloscope. is an AC voltage good enough?
Maybe a cheap logic analyzer like http://www.ebay.com/itm/24MHz-8CH-USB-Logic-Analyzer-/190956566562?
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monettes
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Re: big block Mercedes

Post by monettes »

Here's some info to upgrade your BigBlockMopar 440 to EFI:

1- You can get an intake manifold from Edelbrock with multi-port fuel-injectors:
https://lh4.googleusercontent.com/-yEtcrOIhWyI/UWR9A8sIBmI/AAAAAAAAAH0/EaKWh8rRTww/s912/efi11.jpg

2- CAM Sensor bushing:
http://sdconcepts.com/cam_position_sensor_bushings.html

3- Crank Trigger kit:
http://sdconcepts.com/crank_trigger_kits.html

4- You then use smart coils (with 5V ignitor):
https://www.diyautotune.com/product/ign-1a-race-coil/

This should get you going for multiport EFI and Coil on Plugs on your Big Block Mopar 440 engine.

Have fun!
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kb1gtt
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Re: big block Mercedes

Post by kb1gtt »

On that coil, do you have an explanation / schematic about what "A - Trigger" and "B - signal return" are?
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monettes
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Re: big block Mercedes

Post by monettes »

kb1gtt wrote:On that coil, do you have an explanation / schematic about what "A - Trigger" and "B - signal return" are?
A- is the 5V trigger from the ECU

B- is the GND from the ECU

C- Common GND to engine

D- Battery Ground

E- Constant 12V from battery.

The ECU triggers charging by triggering the 5V A lead.
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Re: big block Mercedes

Post by Dodge_470_B »

Both Accel (ACL 77801) and Holley make a dual trigger distributor the run sequential fuel injection. The Holley one you can get a blank top for if your EFI is running individual coils. I would suggest changing the timing chain for a gear drive to reduce jitter as the cam chain wears.
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